CN103482292B - A kind of automatic stereowarehouse intelligent control method - Google Patents

Abstract

An intelligent control method for an automated three-dimensional warehouse. The warehouse adopts a corbel-type shelf structure and an aisle-type stacker structure. The address identification card corresponds to the ground position of each row of warehouses. Every time a row of warehouses passes by, the horizontal direction addresser sends a pulse signal to the PLC through the addressing baffle to achieve the purpose of column addressing; on the loading platform of the stacker The side is installed with a vertical direction addresser that moves up and down together with the stacker loading platform. Every time it passes through a warehouse, the vertical direction addresser sends a pulse signal through the addressing baffle to write to the PLC to achieve layer addressing. Purpose: The two pulse input signals are used as the counting signals of the internal counter of the PLC, and the current value of the counter is used as the basis for speed control. When the stacker reaches the destination, that is, when the count value of the counter reaches zero, a stop signal is sent to stop the stacker Operation, the present invention has a high degree of automation and is easy to manipulate.

Description

An intelligent control method for an automated three-dimensional warehouse

technical field

The invention belongs to the technical field of three-dimensional warehouses, in particular to an intelligent control system for automatic three-dimensional warehouses.

Background technique

With the rapid development of modern production technology and the continuous prosperity of social materials, the storage of goods in flat warehouses is far from meeting the current needs. Therefore, three-dimensional warehouses have become an important part of production and life. For the three-dimensional warehouse The research is also continuously in-depth.

A three-dimensional warehouse is generally composed of high-rise shelves, storage machinery and equipment, buildings, and control and management facilities. There are many forms of shelves, and the materials are generally made of steel or reinforced concrete. The advantages of steel shelves are small component size, high utilization rate of warehouse space, convenient manufacture, and short installation and construction period. And as the height increases, the advantages of steel shelves over concrete shelves are more obvious. In order to improve the efficiency of cargo loading, unloading and access, automated three-dimensional warehouses generally use boxes or pallets to store goods. The basic function of boxes and pallets is to hold small pieces of materials, and at the same time, it should be convenient for the insertion and storage of transport vehicles and stackers. Handling equipment is an important equipment in an automated warehouse. They are generally driven by electricity and controlled manually or automatically to move goods from one place to another. Conveyor systems must have a high degree of reliability. In the three-dimensional warehouse, there is generally only one set of conveying system. Once a failure occurs, the entire warehouse work will be affected. Therefore, the equipment in each link of the conveying system is required to be reliable, durable and easy to maintain. Set up manual control of the conveying system as a backup.

In recent years, my country's automated warehouse technology has developed rapidly. Despite this, there are not many integrated storage systems that have been built in my country so far. There is a relatively large gap, and the reason is that the lack of automation is a big defect.

Contents of the invention

In order to overcome the above-mentioned shortcomings of the prior art, the object of the present invention is to provide an intelligent control system for an automated three-dimensional warehouse, which has a high degree of automation and is easy to operate.

In order to achieve the above object, the technical scheme adopted in the present invention is:

An intelligent control system for an automated three-dimensional warehouse, the warehouse adopts a corbel-type shelf structure and an aisle-type stacker structure, wherein:

A horizontal addressing device that moves back and forth with the stacker is installed on the bottom beam of the stacker, and its corresponding addressing sheet corresponds to the ground position of each row of warehouses. The horizontal addressing device is a photoelectric switch, each Passing through a row of warehouses, the photoelectric switch sends a pulse signal to the PLC through the address recognition baffle, and the counter inside the PLC counts accordingly to achieve the purpose of row recognition;

On the side of the cargo platform of the stacker, there is a vertical direction address device that moves up and down together with the stacker cargo platform. The vertical direction address device is a photoelectric switch. The address baffle sends out a pulse signal to write to the PLC, and the internal counter of the PLC counts accordingly to achieve the purpose of layer identification;

The two kinds of pulse input signals are used as the counting signals of the PLC internal counter, and the current value of the counter is used as the basis for speed control. When the stacker reaches the destination cargo grid, that is, when the count value of the counter reaches zero, the PLC sends a stop signal to make the stacker The machine stops running.

Assume that the left side of the bottommost layer of the roadway entrance is the first column and the 0th floor, and the distance from the target cargo grid during operation is the S column cargo grid. The column speed control strategy of the stacker is as follows:

$\mathrm{<span\; class="notranslate">\; V</span>}<span\; class="notranslate">\; =</span>\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; 30</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; ></span>\mathrm{<span\; class="notranslate">\; 6</span>}\\ \mathrm{<span\; class="notranslate">\; 15</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; 6</span>}\\ \mathrm{<span\; class="notranslate">\; 5</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; 2</span>}\\ \mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}\end{array}\right.$

The PV value of the counter inside the PLC is used as the basis for speed adjustment. The specific operation is as follows: the operator checks whether there are goods on the stacker outbound platform: if there is, remove the goods; when the stacker is in the original position, select For the warehouse with goods, the stacker is controlled to run in the positive direction of the horizontal direction. Every time it runs to a row of shelves, the counter is decremented by one after the signal input from the sensor, until the PV value on the counter is reduced to 0, and the stacker stops. The PV value is the preset value of the counter, which represents the number of shelves from the destination shelf to the entrance of the roadway.

The layer speed control strategy of the stacker is consistent with the row speed control strategy, also refer to the following formula:

$\mathrm{<span\; class="notranslate">\; V</span>}<span\; class="notranslate">\; =</span>\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; 30</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; ></span>\mathrm{<span\; class="notranslate">\; 6</span>}\\ \mathrm{<span\; class="notranslate">\; 15</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; 6</span>}\\ \mathrm{<span\; class="notranslate">\; 5</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; 2</span>}\\ \mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}\end{array}\right.<span\; class="notranslate">\; .</span>$

The roadway stacker includes a frame, a horizontal walking mechanism, a lifting mechanism, a loading platform and a cargo fork, wherein the frame is composed of an upper beam on the rack sky rail, a lower beam on the rack ground rail, and a connecting frame. The beam is composed of the column of the lower beam. The horizontal walking mechanism is ground-driven, and the traction stacker moves horizontally; the lifting mechanism pulls the loading platform to do vertical lifting movement; Under the traction of the mechanism, the lifting movement is performed; the fork is connected to the platform of the loading platform.

There are two uprights, and the lifting mechanism is located between the two uprights, and is connected with the corresponding uprights through guide wheels. A pulley is arranged above the lifting mechanism, and the lifting motor is connected to the reel through a reducer. Wire rope connection.

The cargo fork includes a sprocket, a chain, a gear, a rack, a lower fork, a middle fork, an upper fork and a bearing. The top plate of the upper fork is connected with the vertical plate, and the vertical plate is equipped with bearings. The fork motor drives the gear to rotate through the sprocket chain, and the gear drives the rack and the middle fork to move. The fork moves along the I-shaped guide rail in the center fork.

The cargo compartment is provided with a through-beam sensor for detecting whether there is goods in the warehouse and a reflective sensor for address identification and limit protection.

Compared with prior art, the beneficial effect of the present invention is:

1. The power control system is controlled by a more stable and reliable AC two-speed motor to improve the stability and safety of the power system. Considering that the vertical running cargo platform cannot fall due to insufficient torque, the vertical motor uses constant torque frequency conversion Inverter (or vector control frequency converter) to improve the stability of its operation, level and fork can use V/F control frequency converter. Considering that the horizontal motor and the fork motor do not run at the same time, the same frequency converter can be used to drive the two motors separately by two AC contactors. Its system structure is shown in Fig. 5.

2. The positioning accuracy of the stacker is improved by selecting the reflective photoelectric sensor as the positioning device, and one addresser (GD1 and GD2) is installed in each of the horizontal and vertical directions. The addressing device in the horizontal direction is installed on the beam at the bottom of the stacker. The addressing sheet corresponds to the ground position of each row of warehouses. GD1 moves back and forth with the stacker. Every time a row of warehouses passes, the photoelectric switch passes through the addressing baffle. Send a pulse signal to write to the PLC, and the internal counter counts accordingly to achieve the purpose of column identification. The vertical direction is similar.

3. Choose the through-beam sensor to detect whether there is goods in the cargo space, so as to improve the detection speed.

4. Select S7-200CPU226 series PLC and corresponding expansion modules to control the system, so as to meet the operating requirements of the system and increase the stability of the system.

5. Choose STEP7 as the development tool of the control system software, which can realize modular development, and at the same time facilitate the configuration of hardware and network, and facilitate the maintenance and upgrading of the system.

Description of drawings

Fig. 1 is a schematic diagram of the composition of the system modules of the present invention.

Fig. 2 is a schematic diagram of the structure of the double-column frame of the present invention.

Fig. 3 is a structural schematic diagram of the lifting device of the present invention.

Fig. 4 is a schematic diagram of the structure of the pallet fork of the present invention.

Fig. 5 is a schematic structural diagram of the control system of the present invention.

Fig. 6 is a schematic structural diagram of the reflective sensor of the present invention.

Fig. 7 is a structural schematic diagram of the through-beam sensor of the present invention.

Fig. 8 is a working block diagram of the control system of the present invention.

Fig. 9 is a graph of column speed control in the present invention.

Detailed ways

The implementation of the present invention will be described in detail below in conjunction with the drawings and examples.

As shown in FIG. 1 , the three-dimensional warehouse system of the present invention is mainly composed of a man-machine interface, a control device, a drive module, a motor brake device, mechanical components and a warehouse module.

The operator inputs commands to the three-dimensional warehouse through the human-machine interface interface, such as sending goods to a certain warehouse, and the human-machine interface interface transmits this command to the control device, and the control device will make a simple judgment based on the command, that is, whether to execute or not. Not executed, such as the position is full, then it will not be executed, so the control device will first accept the feedback information from the position module, if the position is not occupied, the control device will call to execute the The corresponding program of the command is executed, so as to control the drive module connected to it. The function of the drive module is to drive the motor brake device. The operation of the motor brake device will drive the corresponding mechanical parts, and the mechanical parts will move the goods. Transport to the appropriate warehouse, or take out the goods from the appropriate warehouse, so as to achieve the purpose of the operator to pick up and deliver the goods.

The human-machine interface mainly refers to the platform that is operated by humans for machinery or equipment. In the three-dimensional warehouse, the human-machine interface assumes the role of the operator in controlling the normal operation of the three-dimensional warehouse. The operator can issue operation commands to the three-dimensional warehouse through the man-machine interface interface, which includes: the way of goods in and out of the warehouse and the storage location number of the warehouse. In addition, in order to allow the operator to see the selected bin number more clearly, the bin number and current status display can also be added on the man-machine interface.

In the design of the control device, the present invention utilizes a programmable logic controller (PLC). Write the program used to control the work of the three-dimensional warehouse in the PLC controller, including the initialization program, the goods in and out of the warehouse program, the status display program and so on. When the controller receives the command from the man-machine interface, it can make a logical judgment whether it is corresponding, and then call the pre-set program to execute.

The signal of the drive module is mainly input by the control module, and its function is to drive the corresponding motor braking device to work, and to play the role of circuit protection, that is, overvoltage and overcurrent protection.

The motor brake device is mainly used to drive the subsequent mechanical parts to move. The purpose of the movement of the mechanical parts is to move the goods to the appropriate position, and the mechanical parts themselves have no power, so the motor brake device is needed to drive its movement. To transport the goods from the initial position to the warehouse or take them out from the warehouse to the initial position, three issues are mainly considered in terms of actions in this process: take-move-put.

Take, that is, the action of removing goods from a certain location, either at the initial location for storage, or at a certain position.

Moving means to transfer the goods to the designated location, which can be moved to the starting platform or to each warehouse, so it is very important to be able to achieve accurate positioning in this process.

Putting is the action of putting down the goods transferred to the designated place, either at the initial position or in a certain position.

The storage module can generally be designed as a frame structure. In the selection of materials, relatively strong materials should be selected, such as steel or iron materials. In terms of shape design, it is best to arrange them neatly. For example, the most commonly used is an array structure. , such as N×M-type warehouses, that is, horizontal N rows of warehouses and vertical M columns of warehouses are neatly arranged, which is more conducive to the control of the positioning of goods transfer. At the same time, in the design of each storage position, the transmission of the current state information of the storage position should be considered, such as whether the storage position already has goods, otherwise, if the goods are sent to the full storage position, it will cause errors in the operation of the warehouse or damage the goods and the hardware of the warehouse equipment.

According to the external dimensions, weight and other relevant factors of the cargo unit, the present invention adopts the corbel-type shelf. After the shelf form is determined, the cargo grid is naturally formed. The size of the cargo grid depends on the size of the gap between the cargo unit and the shelf column, beam (corbel), and to a certain extent, it is also affected by the shelf structure type and other factors. The specification of the unit shelf in this embodiment is a 5*5 shelf. In order to improve the rigidity and load-bearing capacity of the shelf structure, strengthening treatment is done on the side of the shelf column.

The stacker of the present invention is composed of a frame (upper beam, lower beam, column), a horizontal traveling mechanism, a lifting mechanism, a loading platform, a cargo fork and an electrical control system. Wherein the frame is composed of an upper beam on the rack sky rail, a lower beam on the rack floor rail and a column connecting the upper beam and the lower beam, and the horizontal walking mechanism is ground-driven, and the traction stacker moves horizontally; The lifting mechanism pulls the loading platform to perform vertical lifting movement; the loading platform is located on the frame and performs lifting movement under the traction of the lifting mechanism; the cargo fork is connected to the surface of the loading platform.

As shown in Figures 2 and 3, the gantry structure of the frame adopts a double gantry, that is, there are two columns, and the lifting mechanism 1 is located between the two columns, and is connected with the corresponding column through the guide wheel 3, and the lifting The top of the mechanism 1 is provided with a pulley 2, and the hoisting motor 6 is connected to the reel 4 through the reducer 5, and the reel 5 and the pulley 2 are connected with a wire rope. The diameter of drum 4 and pulley 2 should be the load diameter used, see the crane standard. Drum 4 is a cylinder with grooves, and the angle between the direction of wire rope winding in the groove and the direction of the wire rope when it is wound into the groove is within 4°. The wire rope must be more than 2 turns.

The lifting mechanism is a device that raises the loading platform to a certain height, and it is also responsible for the slight rise and fall of the cargo fork.

As shown in Figure 4, cargo fork of the present invention is made up of motor reducer, sprocket 15, chain, gear 16, rack 17, lower fork 11, middle fork 12, upper fork 13 and bearing 14 etc. The side of the lower fork 11 is equipped with a bearing 14 and fixed on the platform of the loading platform, the lower plate of the middle fork 12 is connected with the I-shaped guide rail, the top plate of the upper fork 13 is connected with the vertical plate, and the vertical plate is equipped with a bearing 14. . The fork motor drives the gear 15 to rotate through the sprocket chain, and the gear drives the rack and the middle fork 12 to move, while the sprocket 17 of the middle fork 12 drives the upper fork 13 through the chain to move along the I-shaped guide rail in the middle fork 12 .

The electric control system of the present invention mainly includes electric drive, control, detection and safety protection, and generally adopts programmable controller, single-chip microcomputer, single-board computer and computer etc. to the control of stacker. The stacker must have automatic address recognition, detection of virtual and real cargo locations, and other detections. The electric drive system must meet the three requirements of speed, stability and accuracy at the same time. The structural design of the stacker must not only meet the strength requirements, but also have sufficient rigidity and meet the precision requirements.

In addition, the safety protection device is also an important part of the stacker, which is set up to prevent sudden accidents, generally including: terminal limit protection, chain protection, positive position detection control, cargo platform rope break protection, power failure protection etc.

The stacker of the present invention involves movement in three directions, the horizontal movement of the X axis, the vertical movement of the Y axis and the telescopic movement of the cargo fork of the Z axis. The selection of the motors in each direction is particularly critical, because the performance of the motors directly affects the performance of the three-dimensional warehouse lifting system. The starting acceleration, smooth running and braking deceleration of the horizontal walking and lifting system are controlled by the traction motor, so the performance of the traction motor directly affects the starting and braking performance of the lifting system. In addition, the leveling accuracy of the lifting system is not only related to the braking distance and braking torque, but also related to the performance of the traction motor. The mechanical characteristics of the traction motor must be able to operate in four quadrants with adjustable speed.

During the operation of the stacker, the traction motor needs to start, brake, rotate forward and reverse frequently, and the load changes greatly. It often works in the key short-term state, electric state, and braking state, which requires high motor requirements. .

According to the nature of the work, the traction motor should have the following characteristics:

(1) It can brake and start frequently.

(2) The starting current is small.

(3) It must have the characteristics of power generation braking, and the speed of the traction system can be controlled by the nature of the motor itself when it is fully loaded down and no-load up.

(4) It must have relatively hard mechanical properties, and it will not cause excessive changes in lifting speed due to changes in the load of the lifting device.

(5) The motor runs smoothly, reliably and with low noise.

Therefore, the horizontal and vertical traction motors of the stacker of the present invention are AC double-speed motors, whose performance meets the requirements of the above-mentioned traction system. Although there will be no acceleration and deceleration process when stretching in the Z-axis direction, starting and braking are quite frequent, so the motor for the telescopic fork in the Z-axis direction uses an AC double-speed motor.

In order to ensure accurate positioning and work efficiency during the operation of the stacker, it is necessary to control the movement speed of the stacker. According to actual needs, design multi-speed operation mode. Speed control is mainly to control the row and layer walking motors. Take column speed control as an example to illustrate the method of speed control: the lowest floor at the entrance of the roadway is the first column and the 0th floor, and the distance from the destination cargo location during operation (the current value of the position positioning counter) is S cargo grids, and the control algorithm is as follows :

$\mathrm{<span\; class="notranslate">\; V</span>}<span\; class="notranslate">\; =</span>\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; 30</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; ></span>\mathrm{<span\; class="notranslate">\; 6</span>}\\ \mathrm{<span\; class="notranslate">\; 15</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; 6</span>}\\ \mathrm{<span\; class="notranslate">\; 5</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; 2</span>}\\ \mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}\end{array}\right.$

The specific process of speed control is as follows. After analyzing the control scheme of the stacker, it can be concluded that the operation curve of the stacker can be summarized as follows: (1) When the distance between the start and end of the operation is 1 or 2 cargo grid lengths, the speed curve C0 is used to run, At this time, Vmax=5; (2) When the running distance is 3, 4, 5, and 6 grid lengths, use the speed curve C1 to run. At this time, Vmax=15. For example, when S=5, the motor will use a larger output power Make the stacker get a greater acceleration, within a short time (about the distance of one cargo box), increase to the maximum speed of 15m/min, and then keep running at this speed until only one cargo box is left, Start to brake and decelerate until it reaches the specified cargo grid, and the speed drops to 0; (3) When the running distance is more than 7 cargo grid lengths, use a similar curve C2 to run, at this time Vmax=30; the speed change process is the same as (2) Similar; these different speed curves can be stored in the positioning module in advance through debugging and testing. The monitoring machine sends the start address and target address to the stacker controller. the running curve. The setting of the speed curve is shown in Figure 9.

Due to the requirement of precise positioning, the present invention needs to use a frequency converter capable of running at a lower frequency. In order to provide sufficient torque when the motor is running at low frequency, and to ensure that the vertically running cargo platform will not fall due to insufficient torque, The vertical motor needs to use a constant torque inverter (or vector control inverter); the horizontal and fork can use a V/F control inverter. The horizontal motor and the cargo motor do not run at the same time, and the same frequency converter can be used to drive the two motors separately by two AC contactors. The structure of the control system is shown in Figure 5.

The positioning of the stacker in the present invention is mainly composed of an address recognition device, and the address recognition device is mainly composed of an address recognition chip and an address recognition device. The addresser can choose infrared photoelectric switch or photoelectric sensor.

Photoelectric switches are controlled by converting changes in light intensity into changes in electrical signals. The infrared photoelectric switch uses near-infrared and infrared rays to detect and distinguish objects. The weak light beam emitted instantaneously by the photoelectric device can be accurately transmitted and received. Photoelectric switches can handle changes in the intensity of light, using light beams to reflect objects, making the light beams return instantly after being emitted over a long distance.

Photoelectric sensors are composed of transmitters, receivers and detection circuits. The transmitter emits a beam of light aimed at the target, and the emitted beam generally comes from a semiconductor light source, a light-emitting diode, and a laser diode. The receiver consists of a photodiode or a phototransistor. In front of the receiver, optical components such as lenses and apertures are installed. Following it is the detection circuit, which is able to filter out the valid signal and apply it. In addition, there are reflective plates and optical fibers among the structural elements of the photoelectric sensor. The triangular reflector is a reflective device with a solid structure. It is composed of small triangular pyramid reflective materials, which can accurately return the light beam from the reflector, and has practical significance.

For precise positioning, an addresser is installed in the horizontal and vertical directions. The horizontal direction addressing device is installed on the beam at the bottom of the stacker. The addressing sheet corresponds to the ground position of each row of warehouses. The pulse signal is written to the PLC, and the internal counter counts accordingly to achieve the purpose of column addressing.

The vertical direction addresser is installed on the side of the loading platform of the corresponding warehouse stacker, and moves up and down together with the loading platform of the stacker, and the photoelectric switch sends out a pulse signal through the addressing baffle to write to the PLC every time a layer of cargo passes through. , the internal counter counts accordingly to achieve the purpose of layer addressing. The pulse input signal of the photoelectric switch is used as the counting signal of the PLC internal address counter, and the current value of the counter is used as the basis for speed control. When the stacker reaches the destination, that is, when the count value of the counter reaches zero, a stop signal is sent to stop the operation. The photoelectric switch in the vertical direction uses the counter inside the PLC to receive the photoelectric pulse. Every time the loading platform passes through a floor, the counter is counted down by 1, so as to achieve the purpose of addressing in the direction of the floor.

The stacker has high requirements on its positioning accuracy. For example, for column positioning, it is required that the stacker can stop on the center line of the target column, and the error should not exceed 2mm. Otherwise, due to the accumulation of errors, it is easy to hit the shelf or other accidents when the fork accesses the container. However, after the stop signal is issued, the stacker will slide a little due to inertia, so it is difficult to achieve precise positioning by counting and addressing alone. For this reason, we combine the address recognition method with the speed regulation of the motor, and the counting state of the counter controls the frequency converter in time through the PLC to make the horizontal and vertical motors decelerate in advance before stopping, which is convenient for braking. After the stop signal is sent out, the fine control of the stacker stopping in time is realized.

The present invention also needs a through-beam sensor for detecting whether there are goods in the warehouse, and a reflective sensor for address recognition, limit protection, and the like.

In the three-dimensional warehouse, the Omron EE-SPY402 groove type and reflective connector type sensor is used for position detection. It adopts the variable dimming type that can resist the surrounding external light interference; it adopts the variable dimming type, which is less susceptible to the influence of external light interference compared with the DC light type; the power supply voltage is DC5-24V large-range voltage output type; it is easy to adjust The optical axis mark; with a light incident indicator light for easy adjustment and action confirmation. The structure of the reflective sensor is shown in Figure 6. When the object moves relative to the sensor, the reflected signal is compared with the original signal to generate a frequency shift, and the integrated circuit amplifies the weak frequency shift signal, and then undergoes Doppler detection, amplification, limiting and other measures, and finally Obtains the output level of the mainstream signal relative to the object movement signal.

The output state of the through-beam sensor is generally NPN output, and the action state of the output transistor can be divided into two types: ON when light is received and ON when light is blocked. Figure 7 shows the configuration of a through-beam sensor that turns ON when light is received. When the 24V voltage is applied to the light-emitting diode LED1, it emits light to the light-emitting diode LED2, LED2 receives the light conduction, the triode conducts, and the output is ON; when the light emitted by the light-emitting diode LED1 is blocked by the object, the light-emitting diode LED2 receives When not, LED2 is not conducting, the triode is not conducting, and the output is OFF.

In the electrical design of the system of the present invention, the motor mainly adopts an AC double-speed motor to control the horizontal movement, the vertical movement and the action of the delivery platform respectively. The sensor adopts through-beam, reflective sensor and micro switch, which is used to complete the detection of goods and limit protection.

The system adopts pulley, guide wheel and steel wire rope as the main transmission mechanism in the mechanism design. When the stacker platform moves to the designated position of the shelf, the delivery table stretches forward to take out or send in the goods. When the goods are taken out or the goods have been sent in, the forks retract backward. The whole system requires three-dimensional position control.

According to the above electrical and mechanical mechanisms, the control system works as shown in Figure 8:

1. The following describes the operation process of picking up the goods:

SETP1 resets the stacker and positions it at the coordinate origin;

SETP2 selects the position number to be operated on the control panel, and displays the storage situation of the position;

SETP3 selects the mode of operation as pick-up or delivery,

If SETP4 is to pick up the goods, then judge whether the alternative position has goods, if not, cancel the operation, otherwise transfer to SETP5;

SETP5 starts the control speed motors of the Y and X axes, the Y axis moves up, the X axis moves to the right, first accelerates and then decelerates to the selected position;

The SETP6Z axis takes the fork and stretches forward at a lower speed to the bottom;

The SETP7Y axis moves up a certain distance at a lower speed and stops;

The SETP8Z axis picks up the fork and retracts at a lower speed;

SETP9 starts the X/Y axis speed control motor, first accelerates and then decelerates, and runs to the outbound platform

SETP10 Z-axis fork stretches forward, Y-axis moves up a certain distance at a lower speed, and stops, and puts the goods on the out-of-warehouse platform

The SETP11 Z axis picks up the fork and retracts at a lower speed;

2. Inventory operations are similar

Claims (5)

1. An intelligent control method for an automated three-dimensional warehouse, the warehouse adopts a corbel-type shelf structure and an aisle-type stacker structure: A horizontal addressing device that moves back and forth with the stacker is installed on the bottom beam of the stacker, and its corresponding addressing sheet corresponds to the ground position of each row of warehouses. The horizontal addressing device is a photoelectric switch, each Passing through a row of warehouses, the photoelectric switch sends a pulse signal to the PLC through the address recognition baffle, and the counter inside the PLC counts accordingly to achieve the purpose of row recognition; On the side of the cargo platform of the stacker, there is a vertical direction address device that moves up and down together with the stacker cargo platform. The vertical direction address device is a photoelectric switch. The address baffle sends out a pulse signal to write to the PLC, and the internal counter of the PLC counts accordingly to achieve the purpose of layer identification; The two pulse signals are used as the counting signals of the PLC internal counter, and the current value of the counter is used as the basis for speed control. When the stacker reaches the destination cargo grid, that is, when the count value of the counter reaches zero, the PLC sends a stop signal to make the stacker stop running; It is characterized in that, Assume that the left side of the bottommost layer of the roadway entrance is the first column and the 0th floor, and the distance from the target cargo grid during operation is the S column cargo grid. The column speed control strategy of the stacker is as follows: $\mathrm{<span\; class="notranslate">\; V</span>}<span\; class="notranslate">\; =</span>\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; 30</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; ></span>\mathrm{<span\; class="notranslate">\; 6</span>}\\ \mathrm{<span\; class="notranslate">\; 15</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; 6</span>}\\ \mathrm{<span\; class="notranslate">\; 5</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; 2</span>}\\ \mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}\end{array}\right.$ The layer speed control strategy of the stacker is as follows: $\mathrm{<span\; class="notranslate">\; V</span>}<span\; class="notranslate">\; =</span>\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; 30</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; ></span>\mathrm{<span\; class="notranslate">\; 6</span>}\\ \mathrm{<span\; class="notranslate">\; 15</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; <</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; 6</span>}\\ \mathrm{<span\; class="notranslate">\; 5</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; min</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; 2</span>}\\ \mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}\end{array}\right.$ The PV value of the counter inside the PLC is used as the basis for speed adjustment. The specific operation is as follows: the operator checks whether there are goods on the stacker outbound platform: if there is, remove the goods; when the stacker is in the original position, select For the warehouse with goods, the stacker is controlled to run in the positive direction of the horizontal direction. Every time it runs to a row of shelves, the counter is decremented by one after the signal input from the sensor, until the PV value on the counter is reduced to 0, and the stacker stops. The PV value is the preset value of the counter, which represents the number of shelves from the destination shelf to the entrance of the roadway. 2. The intelligent control method of the automated three-dimensional warehouse according to claim 1, wherein the roadway stacker comprises a frame, a horizontal traveling mechanism, a lifting mechanism, a loading platform and a cargo fork, wherein the frame It is composed of an upper beam on the rack sky rail, a lower beam on the rack floor rail and a column connecting the upper beam and the lower beam. The horizontal walking mechanism is ground-driven and pulls the stacker to move horizontally; the lifting mechanism pulls The loading platform performs vertical lifting movement; the loading platform is located on the frame and performs lifting movement under the traction of the lifting mechanism; the cargo fork is connected to the surface of the loading platform. 3. The intelligent control method for an automated three-dimensional warehouse according to claim 2, wherein there are two columns, the lifting mechanism is located between the two columns, and is connected to the corresponding column through a guide wheel, and the lifting mechanism is arranged above the two columns. There are pulleys, the hoisting motor is connected to the reel through the reducer, and the reel and the pulley are connected by a wire rope. 4. The intelligent control method of the automated three-dimensional warehouse according to claim 2, wherein the fork comprises a sprocket, a chain, a gear, a rack, a lower fork, a middle fork, an upper fork and a bearing, and the side of the lower fork is installed The bearing is fixed on the platform of the loading platform, the lower plate of the middle fork is connected with the I-shaped guide rail, the top plate of the upper fork is connected with the vertical plate, and the vertical plate is equipped with bearings, and the fork motor drives the gear to rotate through the sprocket chain , the gear drives the rack and the middle fork to move, and the sprocket of the middle fork drives the upper fork to move along the I-shaped guide rail in the middle fork through the chain. 5. The intelligent control method of the automated three-dimensional warehouse according to claim 2, wherein the cargo grid is provided with a through-beam sensor for detecting whether there is goods in the warehouse and a reflective sensor for address recognition and limit protection. sensor.